Abstract Background Large atrial septal defects (ASDs) can cause significant left-to-right shunting, leading to right-sided volume overload and potentially right-sided heart failure, arrhythmias, and pulmonary hypertension. Echocardiographic evidence of right heart chamber dilatation is considered an indication for closure intervention. However, even smaller ASDs, including those that close spontaneously, are associated with increased risk of substantial comorbidities, the cause of which remains unknown. We recently reported that newborns with ASDs exhibit larger atria and right ventricles, along with altered electrocardiographic parameters, suggesting these changes are not necessarily secondary to shunting. Purpose This study investigates whether newborns with ASDs at follow-up in preschool-age still exhibit altered cardiac dimensions in both children with spontaneous closure and patent ASDs. Methods Children with neonatally identified secundum ASDs and controls without interatrial communication from a large, prospective, population-based cohort study were reexamined with transthoracic echocardiography (TTE) at 4-6 years of age. Interatrial communications were classified using a novel diagnostic algorithm identifying ASDs in 6% of newborns. The criteria for ASD where a defect size ≥4 mm, an abnormal location in the inferior part of the septum or if multiple communications were present. The follow-up TTEs were evaluated for patency of the ASD and analyzed according to international guidelines. Echocardiographic parameters, indexed to body surface area (BSA), were compared between children with neonatal ASDs and controls using Student’s T-test. Results We included 290 children with neonatal ASD (median age 5.1 4.8-5.4 years, 56% female, median BSA 0.78 0.75-0.83 m2) and 191 controls (median age 5.2 4.8-5.4 years, 48% female, median BSA 0.79 0.74-0.84 m2). At follow-up, 53 (18%) of the children with neonatal ASD had patent interatrial communication, with 23 still meeting ASD criteria while the rest had diminished to a patent foramen ovale. Children with neonatal ASDs had smaller left ventricular volumes compared to controls (Table), both when including those with spontaneous closure and when looking isolated at those with patent ASD. Those with patent ASDs also had greater right ventricular end-diastolic basal diameter, tricuspid annular plane systolic excursion, and pulmonary valve maximal velocity compared to controls. No other echocardiographic parameters differed significantly (Table). Conclusions Pre-school aged children with neonatal ASD had smaller left ventricular volumes compared to controls, despite the majority having closed spontaneously. Those with patent ASDs also had increased right sided dimensions and function. These findings suggest that altered cardiac dimension in children with ASD are both secondary to shunting and potentially part of the underlying pathogenesis.Table
Dannesbo et al. (Sat,) studied this question.